Effect of doping Ti on the vacancy trapping mechanism for helium in ZrCo from first principles

2019 ◽  
Vol 21 (37) ◽  
pp. 20909-20918
Author(s):  
Qingqing Wang ◽  
Xianggang Kong ◽  
You Yu ◽  
Huilei Han ◽  
Ge Sang ◽  
...  
Keyword(s):  
Point Defects ◽  
First Principles ◽  
Trapping Mechanism ◽  
Macroscopic Properties ◽  
Properties Of Materials ◽  
Vacancy Trapping ◽  
Effect Of Doping

The interactions of dopants with point defects such as that between vacancies and helium can affect helium evolution and ultimately the macroscopic properties of materials.

scholarly journals First-Principles Atomistic Thermodynamics and Configurational Entropy

2020 ◽  
Vol 8 ◽  
Author(s):  
Christopher Sutton ◽  
Sergey V. Levchenko
Keyword(s):  
First Principles ◽  
Configurational Entropy ◽  
Functional Materials ◽  
Expansion Method ◽  
Bulk Materials ◽  
Cluster Expansion Method ◽  
Particle Exchange ◽  
Properties Of Materials ◽  
Atomistic Thermodynamics ◽  
Statistical Effects

In most applications, functional materials operate at finite temperatures and are in contact with a reservoir of atoms or molecules (gas, liquid, or solid). In order to understand the properties of materials at realistic conditions, statistical effects associated with configurational sampling and particle exchange at finite temperatures must consequently be taken into account. In this contribution, we discuss the main concepts behind equilibrium statistical mechanics. We demonstrate how these concepts can be used to predict the behavior of materials at realistic temperatures and pressures within the framework of atomistic thermodynamics. We also introduce and discuss methods for calculating phase diagrams of bulk materials and surfaces as well as point defect concentrations. In particular, we describe approaches for calculating the configurational density of states, which requires the evaluation of the energies of a large number of configurations. The cluster expansion method is therefore also discussed as a numerically efficient approach for evaluating these energies.

Vacancy trapping behaviors of hydrogen in Ti3SiC2: A first-principles study

2014 ◽  
Vol 116 ◽  
pp. 322-327 ◽  
Author(s):  
Yi-Guo Xu ◽  
Xue-Dong Ou ◽  
Xi-Ming Rong
Keyword(s):  
First Principles ◽  
First Principles Study ◽  
Vacancy Trapping

Vacancy trapping behaviors of oxygen in tungsten: A first-principles study

2013 ◽  
Vol 437 (1-3) ◽  
pp. 6-10 ◽  
Author(s):  
Abdullah Alkhamees ◽  
Hong-Bo Zhou ◽  
Yue-Lin Liu ◽  
Shuo Jin ◽  
Ying Zhang ◽  
...  
Keyword(s):  
First Principles ◽  
First Principles Study ◽  
Vacancy Trapping

scholarly journals First Principles Calculations of Defects in Unstable Crystals: Austenitic Iron

2011 ◽  
Vol 1363 ◽  
Author(s):  
G.J. Ackland ◽  
T.P.C. Klaver ◽  
D.J. Hepburn
Keyword(s):  
Point Defects ◽  
First Principles ◽  
Defect Formation ◽  
Single Layer ◽  
Temperature Limit ◽  
Reference State ◽  
First Principles Calculations ◽  
General Picture ◽  
Bcc Iron ◽  
Defect Energies

ABSTRACTFirst principles calculations have given a new insight into the energies of point defects in many different materials, information which cannot be readily obtained from experiment. Most such calculations are done at zero Kelvin, with the assumption that finite temperature effects on defect energies and barriers are small. In some materials, however, the stable crystal structure of interest is mechanically unstable at 0K. In such cases, alternate approaches are needed. Here we present results of first principles calculations of austenitic iron using the VASP code. We determine an appropriate reference state for collinear magnetism to be the antiferromagnetic (001) double-layer (AFM-d) which is both stable and lower in energy than other possible models for the low temperature limit of paramagnetic fcc iron. Another plausible reference state is the antiferromagnetic (001) single layer (AFM-1). We then consider the energetics of dissolving typical alloying impurities (Ni, Cr) in the materials, and their interaction with point defects typical of the irradiated environment. We show that the calculated defect formation energies have fairly high dependence on the reference state chosen: in some cases this is due to instability of the reference state, a problem which does not seem to apply to AFM-d and AFM-1. Furthermore, there is a correlation between local free volume magnetism and energetics. Despite this, a general picture emerge that point defects in austenitic iron have geometries similar to those in simpler, non-magnetic, thermodynamically stable FCC metals. The defect energies are similar to those in BCC iron. The effect of substitutional Ni and Cr on defect properties is weak, rarely more than tenths of eV, so it is unlikely that small amounts of Ni and Cr will have a significant effect on the radiation damage in austenitic iron at high temperatures.

Advances in first-principles modelling of point defects in UO2: f electron correlations and the issue of local energy minima

2013 ◽  
Vol 25 (33) ◽  
pp. 333201 ◽  
Author(s):  
B Dorado ◽  
M Freyss ◽  
B Amadon ◽  
M Bertolus ◽  
G Jomard ◽  
...  
Keyword(s):  
Point Defects ◽  
First Principles ◽  
Local Energy ◽  
Electron Correlations
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